If you want to get an idea of what's available in batiks these days, try this website. You can look/shop by color, by pattern, or by company.
http://www.batiks.com/cgi-bin/Store/store.cgi
This is another good one
http://www.batiksgalore.com/scripts/quiltshop.asp
Have a great time sketching and making this beauty for your MIL. She'll love it, I'm sure!